How do find a supplier of parasitic wasps for birchleaf miner control? From Mississauga, Ontario

The Birch leafminer query – Of the two species of parasitic wasps (Lathrolestes nigricollis and Grypocentrus albipes) introduced for control of the birch leafminer, only L. nigricollis has become widely established. At the level of individual release sites, L. nigricollis has lowered pest density from 50 to <5% of first generation leaves being mined. (Click here.) These wasps were introduced into parts of Quebec and Newfoundland in the 1960s and 1970s and parts of Alberta in the 1990s; Click here for full details. I do not believe that these wasps can be provided to individual homeowners.